Playback apparatus, recording medium, and producing method recording medium

ABSTRACT

A playback apparatus is provided with a reception section and/or a medium holder from which provision date information and playback-permitted period information are provided along with content data. The playback apparatus is also provided with a playback section which plays the content data on the basis of information provided from the reception section and/or the medium holder. With this structure, the playback apparatus plays the content data on the basis of the relationships between the provision date information and the playback-permitted period information. Hence, the playback of the content data can be controlled in accordance with the intention of the content provider.

CROSS-REFERENCE OF THE RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Application No. 2000-389063, filed onDec. 21, 2000, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a playback apparatus, arecording medium and a producing method of the recording medium, whichare applied to the technical field wherein the playback of content datais controlled on the basis of playback period information attached tothat content data.

[0004] 2. Description of the Related Art

[0005] A content data playback apparatus can be provided with not only acontent data playback function but also a clock function which uses aninternal clock to display a date and time. A content data playbackapparatus with such a clock function is in wide use.

[0006] To control the period of time during which content data isplayable, it is thought to provide this type of playback apparatus witha playback control function. The playback control function is a functionof controlling a playback-permitted period for each content data bycomparing playback-permitted period information which a content providerassigns to content data with a value of the internal clock.

[0007] However, the above playback apparatus may have problems if theuser can freely change the value of the internal clock. In this case,the user can change the value of the internal clock to set aplayback-permitted period each time he or she wants to play contentdata. Although changing that value is somewhat troublesome to the user,it is nonetheless possible to play the content data for ever.

[0008] To solve this problem, it is thought to provide the playbackapparatus with a so-called “absolute clock”, which accurately measurestime and does not allow the user to change the value. The absolute clockcan accurately measure time over a period of one decade withoutreference to power outages which may occur in the meantime. However, theplayback apparatus incorporating such an absolute clock is inevitablyhigh in producing cost.

[0009] A “radio clock”, which resembles the absolute value in functionbut is lower in terms of cost, is also known in the art. The radio clockregularly receives a radio wave representing a reference time andadjusts the present time of the clock in accordance therewith. Hence,the time indicated by the radio clock can be regarded as substantiallyaccurate.

[0010] However, the radio clock is not reliable where it cannot receiveradio waves. Since the playback apparatus is often used in indoor areasradio waves do not reach, it is not appropriate to incorporate the radioclock in the playback apparatus.

BRIEF SUMMARY OF THE INVENTION

[0011] Accordingly, an object of the present invention is to provide aplayback apparatus, a recording medium and a producing method of therecording medium, which enable the playback of content data to becontrolled in the manner desired by the content provider by use of aless-costly structure.

[0012] According to one aspect of the present invention, there isprovided a content data playback apparatus comprising: providing meansfor providing not only content data but also provision date informationand playback-permitted period information; and playback means forplaying the content data on the basis of the information provided by theproviding means.

[0013] Since the playback apparatus plays content data on the basis ofthe relationships between the provision date information and theplayback-permitted period information, the structure required is notcostly, and yet the playback of the content data can be controlled inthe manner desired by the content provider. The structure required isnot costly because what the present invention requires in addition tothe structure of the conventional playback apparatus is nothing but amemory for storing provision date information.

[0014] According to the second aspect of the present invention, there isprovided a recording medium storing content data beforehand and beingreadable by a computer. The recording medium comprises: provision dateinformation which is checked by the computer to determine whether or notit is latest, and which is held in the computer when it is determined tobe latest; and playback-permitted period information which is checked bythe computer to determine whether or not a period corresponding to alatest value of the provision date information is satisfied, and whichenables the content data to be played when the period is satisfied.

[0015] Thanks to these features, the recording medium, which producesadvantages similar to those of the first aspect, can be realized readilyand reliably.

[0016] According to the third aspect of the present invention, there isprovided a producing method of the recording medium of the secondaspect. The producing method comprises: preparing an unused-staterecordable medium which can be subjected to recording only once; andrecording provision date information and playback-permitted periodinformation in the unused-state recordable medium along with contentdata.

[0017] Thanks to these features, the recordable medium according to thesecond aspect can be easily realized.

[0018] Additional objects and advantages of the invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0019] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate embodiments of theinvention, and together with the general description given above and thedetailed description of the embodiments given below, serve to explainthe principles of the invention.

[0020]FIG. 1A is a schematic diagram illustrating recording/playbackapparatus according to the first embodiment of the present invention.

[0021]FIG. 1B is a schematic diagram illustrating a prerecorded mediumM2 used in the embodiment.

[0022]FIG. 2 is a schematic diagram illustrating an operation of theembodiment.

[0023]FIG. 3 is also a schematic diagram illustrating an operation ofthe embodiment.

[0024]FIG. 4 is a timing chart illustrating an operation of theembodiment.

[0025]FIG. 5 is a schematic diagram illustrating a playback apparatusaccording to the second embodiment of the present invention.

[0026]FIG. 6 is a schematic diagram illustrating an operation of thesecond embodiment.

[0027]FIG. 7 is timing chart illustrating an operation of the secondembodiment.

[0028]FIG. 8 is a schematic diagram illustrating a recording/playbackapparatus according to the third embodiment of the present invention.

[0029]FIG. 9 is a schematic diagram illustrating an operation of thethird embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0030] Embodiments of the present invention will now be described withreference to the accompanying drawings. In the embodiments describedbelow, playback-permitted period information and provision dateinformation are assigned to content data. The provision date informationis time information representing a preparation date, a broadcast date ora sale date. However, the provision date information is not limited tothis; it may be arbitrary time information representing a point of timebetween a day when content data C becomes ready for provision (i.e., thepreparation date) and a day when it is provided (i.e., the broadcastdate or sale date).

[0031] In any case, the playback apparatus updates the provision dateinformation and records the latest date thereof. In the content dataplayback mode, the playback of the content data is controlled on thebasis of both the recorded provision date information and theplayback-permitted period information of content.

[0032] In other words, approximation information on the present date(provision date information) is provided along with content data. Owingto this feature, the playback can be controlled in accordance with theintention of the content provider (i.e., the playback-permitted periodinformation), without incurring high cost.

[0033] Let us consider the case of a DVD-video disc (Digital VersatileDisc Video Disc) wherein the preparation date information (which isprovision date information) indicates Jan. 1, 2000 and theplayback-permitted period terminates on Mar. 31, 2000.

[0034] This DVD-video disc falls into the hands of the user after Jan.1, 2000, but this date is recorded in the playback apparatus (DVDplayer) with which the DVD-video disc is played. If the DVD-video discshould fall into the hands of the user on Jan. 1, 2000, the preparationdate information is set in such a manner that it represents a date thatis before Dec. 31, 1999.

[0035] In any case, the value of the date memory represents the presentday and time, and yet the structure the date memory employs is much lesscostly than the structure of an absolute clock. The playback of thecontent data is controlled on the basis of both the value of the datememory and the playback-permitted period information. When the presentinvention is reduced to practice, the “date”, such as the provision dateor the preparation date, may represent only a day; alternatively, it mayrepresent both a day and a time.

First Embodiment

[0036]FIG. 1A is a schematic diagram illustrating a playback apparatusaccording to the first embodiment of the present invention. The playbackapparatus is provided with a recording function, and will therefore bereferred to as a recording/playback apparatus. The recording/playbackapparatus 10 includes a date memory 11, an internal clock 12, a mediumholder 13, a reception section 14, a recording section 15 and a playbacksection 16.

[0037] The date memory 11 is preferably a nonvolatile memory. The datememory 11 allows the user to rewrite the data stored therein. Inaddition, the date memory 11 is configured to store latest preparationdate information Dj as memory value T. Preparation date information Djis one of preparation (broadcast) date information D1 to Dj handled bythe recording/playback apparatus 10. If memory value Dj indicates a dateprior to that represented by the preparation date information Di, thenthe memory value Dj is retained without being changed. In other words,the date memory 11 is configured to update the value stored therein onlywhen a date value is greater (or later) than the presently-stored value.

[0038] The preparation date information D is prepared as informationthat is attached to each content data. The preparation date informationD may be replaced with broadcast date information (or present dateinformation) representing a later date, as long as the broadcast dateinformation represents latest date information (a provision date)relating to the provision of content data C. Not only the preparationdate information D described above but also a permitted-period end dateis attached to the content data C.

[0039] Where content data C is stored in a prerecorded data medium M2(such as a DVD-ROM disc) and provided to the user in this format,preparation date information D and permitted-period end date informationE are also recorded in the prerecorded data medium M2.

[0040] Where the content data C is broadcast and is thereby provided tothe user, the preparation date information D and the permitted-periodend date information E are incorporated in a header or controlinformation and broadcast in this state.

[0041] In any case, the preparation date information D andpermitted-period end date information E must be provided from thecontent provider to the user along with the content data C.

[0042] To be precise, date information D and E do not indicate both“time” and “day” but solely “day” in each of the embodiments describedbelow (the same applies to date information A described later). Insteadof this, the date information may be used to indicate both “time” and“day.”

[0043] The internal clock 12 is a clock set by the user. It measures thepresent time and displays “year”, “day”, “hour”, “minute” and “second.”The earliest date that can be measured by the internal clock is notprior to the memory value T of the date memory 11.

[0044] The medium holder 13 detachably holds either a readable/writablerecordable medium M1 or a read-only prerecorded medium M2.

[0045] The recordable medium M1 is a readable/writable (data) recordingmedium in which content data C and a pair of preparation dateinformation D and permitted-period end date information E are recorded.Recordable medium M1 is made of a DVD-RAM, a D-VHS, or the like.

[0046] The prerecorded medium M2 is a read-only data recording medium inwhich content data C and a pair of preparation date information D andpermitted-period end date information E are recorded in advance. Theprerecorded medium M2 is made of a CD-ROM, a DVD-ROM, or the like.

[0047] When the prerecorded medium M2 is made, information may berecorded in it by use of a recording apparatus owned by the maker.Alternatively, the prerecorded medium M2 may be made by making a copy ofa information-recorded master disc by means of a stamper or the like. Ineither case, the prerecorded medium M2 is prepared in the manner shownin FIG. 1B. As shown, an unused-state recording medium M2 _(pre) whichcan be subjected to recording only once is first prepared. Then,provision date information D and playback-permitted period information E(and/or A) are recorded in the unused-state recording medium M2 _(pre)along with content data C. The order in which the content data C andinformation D, E and A are recorded can be arbitrarily determined. Thecontent data and information D, E and A may be recorded simultaneouslyor individually.

[0048] The reception section 14 receives broadcast content data C,preparation date information D, and permitted-period end dateinformation E. Upon receipt of these, the reception section 14 sendsthem to the recording section 15. The medium holder 13 and/or thereception section 15 function as a providing means for providing contentdata, provision date information and playback-permitted periodinformation.

[0049] The recording section 15 has the following functions (f15-1) to(f15-3):

[0050] (f15-1) a function of recording in the recordable medium M1 thecontent data C, preparation date information D and permitted-period enddate information E which are received from the reception section 14;

[0051] (f15-2) a function of comparing the preparation date informationD received from the reception section 14 with the memory value T storedin the date memory 11, and of updating the memory value T of the datememory on the basis of the preparation date information D if thepreparation date information D indicates a date later than that of thememory value T (T<D).

[0052] (f15-3) a function of causing the playback section 16 to play thecontent data C received from the reception section 14.

[0053] The playback section 16 has the following functions (f16-1) to(f16-3):

[0054] (f16-1) a function of reading out the content data C, thepreparation date information D and permitted-period end date informationE from the recordable medium M1 or prerecorded medium M2 held by themedium holder 13, in the medium play mode. This readout function isrealized by employing a light-emitting element, a light-receivingelement, a magnetic head, or another structural component in accordancewith the recording format of the recording medium. The data processing,which is after the data readout operation, is realized by anarbitrarily-determined hardware structure and/or software structure.

[0055] (f16-2) a function of comparing the readout permitted-period enddate information E with the memory value T stored in the date memory 11,and of playing and outputting the content data C unless the memory valueT indicates a date later than that of the permitted-period end dateinformation E (T<E).

[0056] (f16-3) a function of playing and outputting the content data Ctransmitted from the recording section 15, in the broadcast receptionmode.

[0057] A description will now be given as to how the recording/playbackapparatus operates. In the description below, reference will be made tothe case where the content data is broadcast. Reference will also bemade as to how the playback control is made when the content data C,after it is recorded, is viewed or listened to until the daterepresented by the permitted-period end date information.

[0058] As shown in FIG. 2, the recording/playback apparatus 10 isshipped from the factory (the shipping date is Dec. 31, 1999, forexample), with the date memory 11 set at the initial value (e.g., thedate of manufacture or the date of shipment). Let us assume that therecording/playback apparatus 10 is purchased by the user on the same day(ST 1).

[0059] At the time of broadcast reception (e.g., Jan. 1, 2000), therecording/playback apparatus 10 receives content data C1, whichincorporates both preparation (broadcast) date information D1 andpermitted-period end date information E1 (ST 2). In response toreception, the recording section 15 records data C1, D1 and E1 in therecordable medium M1 (ST 3), and the value T of the date memory 11 iscompared with the preparation date information D1. If the preparationdate information D1 represents a date later than that of the value T,then the value T is replaced with the preparation date information D1(ST 4). The received content data C is played and output by the playbacksection 16.

[0060] At the time of playback (which is an arbitrary time and is Apr.15, 2000, for example), the recording/playback apparatus 10 causes theplayback section 16 to compare the value T of the date memory 11 and thepermitted-period end date information E1 stored in the recordable mediumM1. Unless the value T represents a date later than the date of thepermitted-period end date information E1, the content data C is played(ST 5).

[0061] At the time of broadcast reception (which is a time differentfrom the first-time broadcast reception and is May 1, 2000, forexample), the recording/playback apparatus 10 receives other contentdata C2, which incorporates both preparation date information D2 andpermitted-period end date information E2 (ST 6). In response toreception, the recording section 15 records data C2, D2 and E2 inanother recordable medium M1′ (ST 7), and the value T of the date memory11 is compared with the preparation date information D2. If thepreparation date information D2 represents a date later than that of thevalue T, then the value T is replaced with the preparation dateinformation D2 (ST 8). In this case, T=D1 <D2, which means that D2represents a later date. The received content data C2 is played andoutput by the playback section 16.

[0062] Since the relationship E1<T (=D2) is satisfied thereafter, therecording/playback apparatus 10 can no longer play the content data C1recorded in the recordable medium M1 in step ST 3 (ST 9).

[0063] Each time broadcast content data C is received (recorded), theoperation defined in steps ST 2 to ST 5 is repeated. If the content dataC1 that is recorded by a recording/playback apparatus (or a recordingapparatus) is played by another recording/playback apparatus 10′ (or aplayback apparatus), similar processing is executed. In normal use, newcontent data can be played or recorded at any time desired, so that thedate memory 11 of the recording/playback apparatus 10 is updated againand again. Therefore, old content data C can no longer be viewed orlistened to if their permitted-period end dates E expire.

[0064] As can be seen from FIG. 3, the recording/playback apparatus 10functions similarly not only when the recordable medium M1 storingbroadcast information is played but also when the prerecorded medium M2,such as a DVD-video disc, is played.

[0065]FIG. 3 illustrates an operation performed in the case wherecontent data C2 recorded in the prerecorded medium M2 on May 1, 2000 isplayed, in place of the content data broadcast on the same day.

[0066] As shown in FIG. 3, when the prerecorded medium is played (e.g.,on May 1, 2000), the recording/playback apparatus 10 holds theprerecorded medium 2 (ST 6′). At the time, the playback section 16compares the value T of the date memory 11 with the permitted-period enddate information E2 stored in the prerecorded medium M2. Unless thememory value T represents a date later than that of the permitted-periodend date information E2, the content data C2 is played. In addition, therecording/playback apparatus 10 compares the value T of the date memory11 with the preparation date information D2. If the comparison showsthat the preparation date information D2 represents a later date (inwhich case, T=D1<D2, so that D2 represents a later date), the memoryvalue T is replaced with the preparation date information D2 (ST 8′).

[0067] The above operation will be described in more detail withreference to the timing chart shown in FIG. 4. Let us assume thatcontent data (i) to (iv) are provided to the user in this order. In thiscase, the value T of the date memory 11 changes as follows: D1 → D2 → D3→ D4. The playback of content data (i), (ii) and (iv), thepermitted-period end date information E1, E2 and E4 of which are beforethe corresponding ones of D1, D2, D3 and D4 of the date memory 11, isdisabled. The permitted-period end date information E can be sodetermined as to represent “NO LIMIT”, as in content data (iii). In thiscase, the content data (iii) can be played at any time.

[0068] As described above, the recording/playback apparatus 10 of thepresent embodiment plays content data C when the value T of the datememory 11, which is an approximate value of the present date, representsthe permitted-period end date E. Owing to this feature, the structure ofthe embodiment is not costly and can be realized by merely adding thedate memory to the structure of the conventional apparatus. Using thisstructure, the playback of content data can be controlled in such amanner as to follow the intention of the content provider.

[0069] The recording/playback apparatus 10 records provision dateinformation D and playback-permitted period information E in arecordable medium M1 along with content data C. Where the content data Cetc. is provided to the user through broadcasting, the content data C inthe recordable medium M1 can be played as long as the permitted-periodend date information E does not expire.

[0070] The playback control is not limited to that of broadcast contentdata C. It is applicable also to content data C provided in the form ofrecording mediums M1 and M2.

[0071] According to the present embodiment, the playback control isapplied to two kinds of content data C: one is content data that isbroadcast; and the other is content data that is provided in the form ofrecording mediums M1 and M2. Therefore, reference was made to therecording/playback apparatus 10 comprising both the reception section 14and the recording section 15. It should be noted, however, that thepresent invention is applicable to the case where only the playback ofthe content data C provided in the form of recording mediums M1 and M2is controlled. It should be also noted that the reception section 14 andthe recording section 15 can be omitted, thereby providing a dedicatedplayback apparatus. In this case, the playback section 16 is providedwith not only the comparison and playback functions but also an updatingfunction of updating the date memory 11 of the recording section 15.Where the playback control is applied only to broadcast content data C,the medium holder 13 is omitted as well as the related recordingfunction of the recording section 15, thereby providing a playbackapparatus.

[0072] The present embodiment is particularly advantageous when it isapplied to content data that should be provided with a certain kind ofexpiration date.

Second Embodiment

[0073]FIG. 5 is a schematic diagram illustrating a playback apparatusaccording to the second embodiment of the present invention. The samereferences as used in FIG. 1A are used to denote similar orcorresponding structural elements, and a detailed description of suchelements will be omitted herein. Therefore, a description will be givenof the features that distinguish the second embodiment from the firstembodiment. Likewise, a repetitive description will be omitted inconnected with the third and subsequent embodiments.

[0074] According to the second embodiment, content data C cannot beplayed at first, which is just the opposite to the first embodiment. Theplayback of the content data C is permitted after a use-period startdate A. More specifically, the second embodiment does not employ areception section 14 or a recording section 15, such as that used in thefirst embodiment. In place of the playback section 16 of the firstembodiment, the second embodiment employs a playback section 16 a thatenables playback of content data C from the use-period start date A. Tobe more specific, the playback section 16 a has the following functions(f16 a-1) to (f16 a-3):

[0075] (f16 a-1) a function of reading out content data C, preparationdate information D and use-period start date information A from arecordable medium M1 or a prerecorded medium M2 held by a medium holder13.

[0076] (f16 a-2) a function of comparing the readout preparation dateinformation D with the memory value T stored in the date memory 11, andof updating the memory value T of the date memory on the basis of thepreparation date information D when this information represents a datelater than the memory value T (i.e., when the value of the information Dis greater than the memory value: T<D).

[0077] (f16 a-3) a function of comparing the readout use-period startdate information A with the memory value T stored in the date memory 11,and of playing and outputting content data C when the date representedby the memory value T is later than the date represented by thepermitted-period end date information E (i.e., A≦T, D).

[0078] In each of the recordable medium M1 and the prerecorded mediumM2, use-period start date information A (not the permitted-period enddate information E) is recorded along with content data C andpreparation date information D.

[0079] A description will now be given as to how the playback apparatusof the above structure operates. In the description below, referencewill be made to the playback control performed when the content data Crecorded in the prerecorded medium M2 can be played from the date of theuse-period start date information A.

[0080] As shown in FIG. 6, the playback apparatus 10 is shipped from thefactory (the shipping date is Dec. 31, 1999, for example), with the datememory 11 set at the initial value (e.g., the date of manufacture or thedate of shipment). Let us assume that the playback apparatus 10 ispurchased by the user on the same day (ST 11).

[0081] When a first medium is played (e.g., on Jan. 1, 2000), theplayback apparatus 10 a plays the prerecorded medium M2 ₁, in whichpreparation date information D1, use-period start date information A1and content data C1 are recorded. At the time, the playback section 16 acompares the value T of the date memory 11 with the preparation dateinformation D1. If the preparation date information D1 represents a datelater than the date of the memory value T, then this value T is replacedwith the preparation date information D1 (ST 12).

[0082] Next, the playback section 16 a of the playback apparatus 10 acompares use-period start date information A1 with the memory value D1of the date memory 11 (ST 13). Since, in this case, the comparison showsthat the date represented by the memory value D1 is prior to the daterepresented by the use-period start date information A1 (D1<A1), theplayback of the content data C1 is disabled.

[0083] Thereafter, the updating processing of the memory value D isexecuted in step ST 12, and the playback enabling/disabling operation isperformed based on the comparison processing of step ST 13.

[0084] When another medium is played (e.g., on Apr. 15, 2000), theplayback section 16 a of the playback apparatus 10 a executes step ST 12so as to update the memory value D1 on the basis of D2 (which representsMar. 1, 2000, for example). When the playback section 16 executes stepST 13, the date represented by the memory value D2 is already after thedate represented by the use-period start date information A2 (e.g., Mar.1, 2000). Hence, the content data D2 is played.

[0085] When a third medium is played (e.g., on May 1, 2000), memoryvalue D2 is replaced with memory value D3, but the date represented bythis value is before the date represented by the use-period start dateinformation A3. Hence, the playback of content data D3 is disabled.

[0086] When the third medium is played (on May 1, 2000), the date (May1, 2000) represented by the memory value D3 is after the date (Mar. 31,2000) represented by the use-period start date information A1 of theprerecorded medium M2 ₁. Therefore, the content data C1 of the firstprerecorded medium M2 ₁ can be played at any time desired.

[0087] In normal use, what is played is new content data C, as describedabove. Therefore, the date memory 11 of the playback apparatus 10 a isupdated consecutively. In other words, the content data C, which cannotbe played at first, becomes playable one after another.

[0088] The above operation will now be described in more detail, withreference to the timing chart shown in FIG. 7. Let us assume thatcontent data (i) to (iv) are provided to the user in this order. In thiscase, the value T of the date memory 11 changes as follows: D1 → D2 → D3→ D4. The playback of content data (i), (ii) and (iii), the use-periodstart date information A1, A2 and A3 of which are after thecorresponding ones of D1, D2, D3 and D4 of the date memory 11, ispermitted. Although not shown, content data (iv) becomes playable whenthe value D of the date memory 11 represents a date that is after thedate of the use-period start date information A.

[0089] As described above, the second embodiment produces advantagessimilar to those of the first embodiment. In particular, the playbackcontrol wherein data becomes playable after the use-period start date Ais realized instead of the aforesaid playback control based on thepermitted-period end date E. The second embodiment is advantageousparticularly when content data on an unreleased movie is distributedbeforehand and is made playable after the release date of that movie.

Third Embodiment

[0090]FIG. 8 is a schematic view illustrating a recording/playbackapparatus according to the third embodiment of the present invention.The third embodiment is practically a modification of the firstembodiment in that content data which cannot be played at first is madeplayable after the use-period start date A. The recording/playbackapparatus can process broadcast content as well as a prerecorded mediumM2.

[0091] As shown in FIG. 8, the recording/playback apparatus 10 b of thethird embodiment functions as a playback apparatus 10 b in which theplayback section 16 shown in FIG. 1A is replaced with playback section16 b. This playback section 16 b enables content data C to becomeplayable after the use-period start date A.

[0092] More specifically, the playback section 16 b is provided with thefollowing functions (f16 b-1) to (f16 b-3):

[0093] (f16 b-1) a function of reading out the content data C, thepreparation date information D and use-period start date information Afrom the recordable medium M1 or prerecorded medium M2 held by themedium holder 13, in the medium play mode.

[0094] (f16 b-2) a function of comparing the readout use-period endstart information A with the memory value T stored in the date memory11, and of playing and outputting the content data C after the memoryvalue T indicates a date later than the date of the use-period startdate information.

[0095] (f16 b-3) a function of playing and outputting the content data Ctransmitted from the recording section 15, in the broadcast receptionmode.

[0096] The recording section 14 and the recording section 15 operate ina similar manner to that described above except that thepermitted-period end date information E is replaced with the use-periodstart date information A.

[0097] In each of the recordable medium M1 and the prerecorded mediumM2, use-period start date information A (not the permitted-period enddate information E) is recorded along with content data C andpreparation date information D.

[0098] A description will now be given as to how the recording/playbackapparatus of the above structure operates.

[0099] As shown in FIG. 9, the recording/playback apparatus 10 bfunctions in a similar manner to that illustrated in FIG. 6 when it isshipped from the factory (on Dec. 31, 1999, for example) and when it isused for playing a medium (on Jan. 1, 2000, for example).

[0100] At the time of broadcast reception (which is Mar. 1, 2000, forexample), the recording/playback apparatus 10 b receives content dataC2, which incorporates both preparation (broadcast) date information D2and use-period start date information A2 (ST 21). In response toreception, the recording section 15 b records data C2, D2 and A2 inrecordable medium M1 (ST 22), and the value T of the date memory 11 iscompared with the preparation date information D2. If the preparationdate information D2 represents a date later than that of the value T,then the value T is replaced with the preparation date information D2(ST 23).

[0101] Then, the playback section 16 b of the recording/playingapparatus 10 b compares the use-period start date information A2 withthe memory value D2 of the date memory 11. Since the comparison showsthat the date represented by the memory value D2 is after the daterepresented by the use-period start date information A2 (A2≦D2), thecontent data C2 is played. It should be noted that the content data C2stored in the recording medium M2 ₂ can be played at any time since thememory value D2 represents a date (Mar. 1, 2000) later than the date(Mar. 1, 2000) of the use-period start date information A2.

[0102] The memory value D2 is updated to D3 when another medium isplayed (on May 1, 2000, for example). Despite this, the playback of thecontent data D3 is disabled because D3<A3.

[0103] In normal use, the date memory 11 is sequentially updated eachtime new content data C is played. Therefore, content data C that cannotbe played at first becomes playable.

[0104] As described above, the third embodiment produces similaradvantages to those of the second embodiment. In addition, the thirdembodiment is advantageous particularly in that the playback ofbroadcast content data C can be controlled.

Fourth Embodiment

[0105] Next, a description will be given of a recording/playbackapparatus according to the fourth embodiment of the present invention.

[0106] The fourth embodiment is an example of a manner in which thefirst to the third embodiments are combined.

[0107] To be more specific, the fourth embodiment combines the condition(T≦E) under which content data is played in the first embodiment withthe condition (A≦T) under which content data is played in the second andthird embodiments.

[0108] According to the fourth embodiment, content data C is playablewhere the playback condition is a combination of those stated above(i.e., A≦T≦E), i.e., where the value T of the date memory 11 is laterthan the use-period start date A and before the permitted-period enddate E.

[0109] Thanks to this feature, the fourth embodiment produces theadvantages of the first to third embodiments simultaneously. That is,content data is playable only in the period between the use-period startdate A and the permitted-period end date E. Hence, the playback controlis more flexible in the fourth embodiment than in the precedingembodiments. The fourth embodiment is particularly advantageous whencontent data C should be released only within a given period of time asin the case of promotion content.

[0110] The fourth embodiment can be modified such that it is applied tocontent data C which should not be released only within a specificperiod of time. In addition, two or more playback-permitted periods canbe determined. For example, a first playback-permitted period havingstart and end dates may be combined with a second playback-permittedperiod having start and end dates in an arbitrary manner. Regardless ofthe manner in which a playback-permitted period is determined, the startand/or end date of this period is contained in playback-permitted periodinformation. Hence, playback control can be performed in a desirablefashion in accordance with the playback-permitted period information.

[0111] The technology described in relation to the above embodiments canbe embodied as a program executable by a computer. The program can bedistributed to people after being stored in recording mediums, includinga magnetic disk (e.g., a floppy disk or a hard disk), an optical disk(e.g., a CD-ROM or a DVD), a magneto-optical disk (MO) or asemiconductor memory.

[0112] The recording mediums can use any recording format as long asthey can store a program and are readable by a computer.

[0113] An OS (Operating System) which a computer executes on the basisof a program installed on a computer from a recording medium, MW(middleware) such as database management software, network software,etc. may be part of the processing that realizes the present embodiment.

[0114] A playback apparatus according to the present invention coversnot only an apparatus whose function is limited to playback (namely, aplayback apparatus) but also an apparatus provided with a recordingfunction as well (recording/playback apparatus).

[0115] Moreover, a recording medium used in the present invention is notlimited to a medium that is independent of a computer; it may be anykind of recording medium as long as it can store or temporarily store aprogram downloaded from a LAN or the Internet.

[0116] Two or more recording mediums may be used. In other words, thepresent invention covers the case where the processing of the embodimentis executed by use of two or more recording mediums. It should be alsonoted that the recording mediums may be of any structure as long as theyfulfill the functions required.

[0117] The computer used in the present invention executes theprocessing on the basis of the program stored in a storage medium. Aslong as this function is satisfied, the computer may be of anystructure. It may be a single personal computer, a system wherein aplurality of apparatuses are connected as a network, etc.

[0118] The computer used in the present invention is not limited to apersonal computer; it may be an operation executing apparatus, amicrocomputer or the like that is included in an information processingapparatus. The concept “computer” used in the present invention isintended to mean any kind of apparatus or device that can achieve thefunctions of the present invention on the basis of a program.

[0119] The present invention is not limited to the embodiments describedabove. When reduced to practice, each of the embodiments described abovecan be modified in various manners without departing from the spirit ofthe invention. The embodiments described above can be combined, if sodesired. In such a combination, advantages produced may be unique tothat combination. It should be noted that the embodiments containinventions of various stages, and the structural elements of theinventions can be modified to derive other inventions. If an inventionis derived by omitting some structural elements from the embodiments,the omitted structural elements can be compensated for with knowntechnology when the derived invention is reduced to practice.

[0120] Lastly, the present invention can be modified in various mannerswithout departing from the spirit of the invention.

[0121] Additional advantages and modifications will readily occur tothose skilled in the art. Therefore, the invention in its broaderaspects is not limited to the specific details and representativeembodiments shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

What is claimed is:
 1. A playback apparatus for playing content data,comprising: providing means for providing not only the content data butalso provision date information and playback-permitted periodinformation; and playback means for playing the content data on thebasis of the information provided by the providing means.
 2. A playbackapparatus according to claim 1, further comprising: a date memory thatstores provision date information representing a latest value providedby the providing means.
 3. A playback apparatus according to claim 1,further comprising: a medium holder for detachably holding a recordingmedium which is externally provided; and recording means for recordingprovision date information and playback-permitted period informationalong with the content data, in the recording medium held by the mediumholder.
 4. A playback apparatus according to claim 2, furthercomprising: a medium holder for detachably holding a recording mediumwhich is externally provided; and recording means for recordingprovision date information and playback-permitted period informationalong with the content data, in the recording medium held by the mediumholder.
 5. A playback apparatus according to claim 2, wherein saidplayback means plays the content data when the provision dateinformation stored in the date memory corresponds to theplayback-permitted period information.
 6. A playback apparatus accordingto claim 5, wherein said playback-permitted period informationrepresents an end date of a playback-permitted date and/or a start datethereof.
 7. A recording medium storing content data beforehand and beingreadable by a computer, said recording medium comprising: provision-dateinformation checked by the computer and determined to be latest or not,said provision date information being held in the computer when theprovision date information is determined to be latest; andplayback-permitted period information which is checked by the computerto determine whether or not a period corresponding to a latest value ofthe provision date information is satisfied, and which enables playbackof the content data when said period is satisfied.
 8. A producing methodfor producing a recording medium described in claim 7, said producingmethod comprising: preparing an unused-state recording medium which canbe subjected to recording only once; and recording the provision dateinformation and the playback-permitted period information in theunused-state recording medium along with the content data.